#!/usr/bin/perl --
use strict;
use warnings;
use HTML::TreeBuilder;
Main(@ARGV);
exit(0);
sub Main {
my $html = '
';
my $tree = HTML::TreeBuilder->new();
$tree->parse($html);
local $\ = $/;
print $_->as_HTML
for $tree->look_down( qw' _tag img ',
sub { not defined $_[0]->attr('alt') } );
print '---';
print $_->as_HTML
for $tree->look_down( qw' _tag img ',
sub { not length $_[0]->attr('alt') } );
print '---';
$_->attr( alt => MAlt($_) )
for $tree->look_down( qw' _tag img ',
sub { not length $_[0]->attr('alt') } );
print $_->as_HTML for $tree->look_down(qw' _tag img ');
} ## end sub Main
sub MAlt { '!' . $_[0]->attr('src') }
__END__
---
---